Intracranial extramedullary hematopoiesis in beta-thalassemia

Report of a Rare Case of Intracranial Extramedullary Hematopoiesis Mimicking a Brain Tumor

Failure of the bone marrow to maintain adequate blood cell production to match blood metabolic demand incites the production of cell lines outside the bone marrow, which is known as extramedullary hematopoiesis. Herein, we are reporting an 80-year-old male patient who presented with two weeks of worsening headaches and behavioral changes. Labs showed thrombocytosis and imaging showed a large right-sided hemorrhagic brain mass. No evidence of malignancy was seen elsewhere. Brain mass biopsy showed intracranial extramedullary hematopoiesis (IEMH) and bone marrow biopsy confirmed the diagnosis of essential thrombocythemia (ET)/myelofibrosis. This case adds to a few reported cases of IEMH, and to the best of our knowledge, this is the first reported case of IEMH in association with ET. It helps remind clinicians to keep IEMH in the differential diagnosis of those presenting with signs and symptoms of elevated intracranial pressure (ICP) and a newly found brain mass on the background of previously diagnosed or suspected myeloproliferative neoplasms.

Intracranial extramedullary hematopoiesis in a patient with beta-thalassemia presenting with head trauma

Background:

Beta-thalassemia is an inherited hemoglobinopathy, whereby reduced or absent expression of beta-globin genes causes impaired erythropoiesis. Extramedullary hematopoiesis (EMH) occurs in 1% of all patients with beta-thalassemia major receiving regular transfusions and is exceedingly rare intracranially.

Case Description:

We report a case of a male in his 20s with beta thalassemia who presented with head trauma found to have intracranial EMH mimicking multiple extra-axial hematomas. Making the correct diagnosis was critical in avoiding prolonged neuromonitoring and unnecessary interventions.

Conclusion:

Intracranial extramedullary hematopoietic pseudotumor is an exceedingly rare entity and seldom appears in a neurosurgeon’s differential diagnosis. This case illustrates how this condition can easily mimic an acute intracranial hemorrhage in a patient with beta-thalassemia who presents with head trauma. We review the topic to further inform clinicians who may encounter this condition in their practice.

Neuroimaging Findings in Pediatric Patients with Thalassemia Major

Background: Cranial magnetic resonance imaging (MRI) studies about iron accumulation in children with thalassemia major are quite limited. Aim: This study aimed to detect neurological findings with cranial MRIs in the pediatric patients with thalassemia major who did not develop any neurological complications. Materials and Methods: Pediatric patients with thalassemia major who followed in the Pediatric Hematology Unit between 1 July 2017 and 1 January 2019 were included in the study. The patients underwent cranial MRI scans. Results: A total of 30 patients were included. The median age was 15 (range from 4–18) years old. We found that 7 patients had a splenectomy and 19 of the remaining 23 patients had splenomegaly. In addition, 13 of the patients had hepatomegaly, 10 had skeletal deformities, and 17 had growth retardation. The mean ferritin level was 3772.3 ± 2524.8. We detected various pathologies on cranial MRI images of 10 (33.3%) patients. In 3 of these patients, millimeter-sized ischemia-compatible lesions were found in the cerebral white matter, which did not fit any arterial area, and 5 patients had hyperintense lesions in the basal ganglia. Conclusion: Our study is valuable since 1/3 of our pediatric patients with thalassemia major were detected with intracranial pathology.

Extramedullary Hematopoiesis in the Dura Mater During Treatment of a CNS Embryonal Tumor

Extramedullary hematopoiesis (EMH) is hematopoiesis occurring outside of the bone marrow. It has been reported to develop in abdominal organs or lymph nodes after chemotherapy. Here, the authors describe a patient with a localized central nervous system embryonal tumor who, during intensive chemotherapy, developed dural nodules. Biopsy revealed these nodules to be EMH. Without a pathologic diagnosis, this may have been considered disease progression, altering the patient's treatment plan. This report intends to serve as a reminder that EMH should be included in the differential diagnosis of suspicious lesions and highlights the importance of their biopsy because of potential management implications.

Marrow outside marrow: imaging of extramedullary haematopoiesis

Extramedullary haematopoiesis (EMH) refers to the formation of non-neoplastic blood cell lines outside the bone marrow and is a common incidental finding when patients with haematological disorders are imaged. EMH presenting as mass (tumefactive EMH) has long been a radiological conundrum as it resembles neoplasms. Several imaging findings have been described in EMH, and these vary depending on the activity of the underlying haematopoiesis. The older lesions are easier to diagnose as they often demonstrate characteristic findings such as haemosiderin and fat deposition. In comparison, the newer, actively haematopoietic lesions often mimic neoplasms. Molecular imaging, particularly ^99mTc labelled sulphur colloid scintigraphy, may be helpful in such cases. Although imaging is extremely useful in detecting and characterising EMH, imaging alone is often non-diagnostic as no single mass shows all the typical findings. Hence, a judgement based on the clinical background, combination of imaging findings, and slow interval growth may be more appropriate and practical in making the correct diagnosis. In every case, an effort has to be made in providing an imaging-based diagnosis as it may prevent a potentially risky biopsy. When confident differentiation is not possible, biopsy has to be resorted to. This article describes the causes, pathophysiology, and theories underlying the genesis of EMH, followed by the general and location-specific imaging findings. The purpose is to provide a thorough understanding of the condition as well as enable the clinical radiologist in making an imaging-based diagnosis whenever possible and identify the situations where biopsy has to be performed.

Intracranial Hematopoiesis in Beta Thalassemia: A Case Series

Extramedullary hematopoiesis (EMH) is a normal response to failure of hematopoiesis at its normal site i.e., bone marrow. It is a manifestation of many congenital hemolytic anemias and marrow failure secondary to myelodysplastic syndromes. Usually, extramedullary myeloid proliferation occurs in liver, spleen and lymph nodes. However, there are many unusual sites where EMH can occur. The authors report two cases of intracranial extramedullary hematopoiesis in beta thalassemia. In one of these patients, epidural soft tissue was detected along frontal and parietal convexities causing compression of brain parenchyma leading to raised intracranial tension and sagging of brain stem, corpus callosum and herniation of cerebellar tonsils. The other case had a similar but unilateral epidural soft tissue. Expansion of diploic spaces of skull was seen in both these cases. As myeloid proliferation is slow, it presents with subtle symptoms of headache and gradually progressive lower limb weakness. A high index of clinical suspicion coupled with imaging findings is the only way to confirm the diagnosis.

A common complication of myelofibrosis presenting as a rare finding in cerebrospinal fluid cytology

Herein, we present a rare case of intracranial extramedullary hematopoiesis (EMH) diagnosed by cerebrospinal fluid (CSF) cytology and describe the clinical presentation, radiologic, and pathologic findings. A 65 year-old man with a history of progressing primary myelofibrosis was admitted for headaches and right facial numbness. A brain MRI revealed focal abnormalities that were suspicious for leptomeningeal involvement of acute leukemia. Cytologic examination of CSF demonstrated a hypercellular specimen composed of hematopoietic cells including few blasts, as well as maturing red blood cells and granulocytic cells. The integration of morphologic findings, peripheral blood and bone marrow counts, as well as flow cytometric analysis of CSF and bone marrow, excluded leptomeningeal involvement by leukemic blasts and helped establish the diagnosis of intracranial EMH. Inclusion of EMH in the differential diagnosis of intracranial pathology in patients with known conditions predisposing them to EMH is important because recognizing this rare event has implications for treatment and prognosis.

Intracranial extramedullary hematopoiesis: a rare cause of headaches

BACKGROUND

Ectopic bone marrow production, known as extramedullary hematopoiesis, may result in symptoms due to compression on normal structures. We present the multimodality imaging findings and subsequent management of a rare case of symptomatic extramedullary hematopoiesis within the calvarium.

METHODS

Case report.

RESULTS

A 54-year-old male with a history of myelofibrosis and no previous diagnosis of a headache disorder presented to the emergency department with worsening severe bilateral headaches. A nonenhanced CT of the brain was performed and diffuse extra-axial nodular hyperdensities were visualized. MRI of the brain demonstrated diffuse extra-axial avidly enhancing nodular masses, dural thickening and marked susceptibility. No paravertebral masses, typical for extramedullary hematopoiesis, were present in the chest or abdomen. Although the clinical team considered a biopsy to confirm the diagnosis, we suggested a noninvasive confirmatory test. The subsequent Tc99m sulfur colloid scan corroborated the diagnosis. The patient was then referred to radiation oncology for treatment.

CONCLUSION

In summary, extramedullary hematopoiesis is a hematologic compensatory disorder that rarely occurs within the CNS and may cause neurological compromise due to compression on underlying structures. The diagnosis can be made with noninvasive imaging and treated with low dose radiation therapy.